1. Field of the Invention:
The present invention relates to an image recording apparatus having sheet stackers for storing discharged sheets of recording paper.
2. Description of the Prior Art:
One conventional image recording apparatus in the form of an electrostatic plotter is shown in FIGS. 18 and 19 of the accompanying drawings. As shown in FIG. 18, the electrostatic plotter has a roll 1 of electrostatic recording paper for supplying an elongated continuous recording paper, a recording head 2 for recording an electrostatic latent image on the recording paper, a developing unit 3 for developing the latent image into a visible image, a pair of upper and lower feed rollers 4 for drawing the recording paper from the roll 1 through the developing unit 3 and feeding the recording paper with the developed visible image thereon, and a cutting unit 5 for cutting the recording paper into a sheet with the visible image recorded thereon.
The cutting unit 5 comprises a pair of inlet rollers 6 positioned near a paper inlet for introducing the recording paper into the cutting unit 5, a pair of feed rollers 7 for feeding the cut sheet through the cutting unit 5, a pair of discharge rollers 8 for discharging the sheet out of the cutting unit 5 in an X direction which is the longitudinal direction of the recording paper, a Y-direction cutter 9 for cutting off the recording sheet in a Y direction which is the transverse direction of the recording sheet perpendicular to the X direction, and an X-direction cutter (not shown) for cutting off the recording paper in the X direction. The cutting unit 5 is mounted on an upper frame which is pivotally movable about a hinge 10 so that it can angularly move upwardly away from the plotter proper when the roll 1 is to be replaced, as shown in FIG. 19.
The electrostatic plotter also includes a sheet guide 11 for guiding sheets discharged from the cutting unit 5.
The electrostatic plotter operates as follows: First, the upper frame on which the cutting unit 5 is mounted are angularly moved upwardly as shown in FIG. 19, and a roll 1 of electrostatic recording paper is set in place in the plotter proper by the operator who is standing on the lefthand side (as viewed in FIG. 19) of the plotter. Then, the operator pulls the recording sheet from the roll 1 and guides the recording paper through the recording head 2 and the developing unit 3 until the leading end of the recording paper extends a certain length from the lower feed roller 4. The operator lowers the cutting unit 5 down against the plotter proper, and places the leading end of the recording paper between the inlet rollers 6 of the cutting unit 5. The electrostatic plotter is now ready to record desired image on the recording paper. In a recording process, an electrostatic latent image is formed on the recording paper by the recording head 2, and then developed into a visible image by the developing unit 3. The recording paper is then fed by the feed rollers 4 and introduced into the cutting unit 5 by the inlet rollers 6. In response to a command for cutting off the recording paper in the Y direction, the inlet rollers 6, the feed rollers 7, and the discharge rollers 8 are stopped, and the Y-direction cutter 9 moves in the Y direction to cut off the recording paper into a sheet of a selected length with the developed image carried thereon. Thereafter, the feed rollers 7 and the discharge rollers 8 are rotated to discharge the cut sheet out of the cutting unit 5. The discharged sheet is guided by the sheet guide 11 so that it can readily be picked up by the operator. Then, the inlet rollers 6 are rotated again. To cut off the recording sheet to a desired width, the X-direction cutter is moved in the X direction while the inlet rollers 6, the feed rollers 7, and the discharge rollers 8 are in operation.
To supply the plotter with new recording paper, it is necessary to set a new roll 1 of recording paper in the plotter proper. Usually, an unused roll 1 of recording paper has a weight of about 10 kg. Therefore, it requires considerably heavy labor for the operator to place a new roll 1 of recording paper into the plotter because the roll 1 has to be set in place far away from the side of the plotter where the operator is standing. Cut sheets are discharged from the cutting unit 5 to the side of the plotter that is remote from the operator. Accordingly, spaces wide enough for the operator to freely get in and out of should be provided on the opposite sides of the plotter. This space requirement poses a limitation on the location where the plotter can be installed. Another problem is that cut sheets are discharged into one place without being sorted. Therefore, it is necessary for the operator to sort the discharged sheets according to size or to sort out any unrecorded waste sheets between recorded images.